1) Field of the Invention
This invention relates to a semiconductor substrate processing apparatus.
2) Discussion of Related Art
Integrated circuits are typically formed on semiconductor wafers. The formation of the integrated circuits may include numerous processing steps such as deposition of various layers, etching some of the layers, and multiple bakes.
Often the processing of semiconductor wafers takes place in large wafer processing machines. One of the components found in these machines are known as modules. These modules may receive a semiconductor wafer from a another component, place the wafer on a wafer support that is able to spin about its central axis, and dispense a solvent or solution onto the wafer as one of the many steps included in wafer processing. The solvent may be dispensed onto the wafers from a dispense head that is moved into a position over the wafer. Typically, the solvent is fed into inlets of the dispense head through a valve and dispensed onto the wafer through nozzles on the dispense head.
As the solvent is dispensed, some of the solvent often splashes off the wafer. In order to protect other components in the system, catch cups are typically attached to the modules. One portion, the top section, of the catch cup completely surrounds the wafer. Another portion, the mid-section, surrounds the wafer chuck and is below the wafer itself.
Solvent that splashes off the wafer outwards onto the top section of the catch cup often bounces off the top section and splashes back onto either wafer or the dispense head, from where it drips onto the wafer. This extra solvent can damage the integrated circuits that are being formed on the wafer. Solvent may also get between the bottom surface of the wafer and the mid-section of the catch cup. The mid-section of the catch cup typically has flat, horizontal surfaces that allow the solvent to stand and dry. The dried solvent can build up and eventually damage the bottom surface of the wafers.